1. Field of the Invention
The present invention relates to the field of spinning machines and more particularly, the invention relates to the fine cleaning of textile fibers and to a method of fine cleaning of textile fibers and an apparatus for performing the method.
2. Description of the Related Art
Textile fibers, especially cotton fibers, are subjected to coarse cleaning after the bales have been opened, during which the coarse contaminants are removed. The fine cleaning follows after the coarse cleaning, during which all of the particles of dirt remaining in the fibers after the coarse cleaning are to be removed to the greatest extent possible. The fibers then go to the next spinning preparatory step after undergoing the fine cleaning operation, such as to the carding machine, for example.
The fine cleaning must be so arranged that all of the contaminants contained in the fibers from every origin must be removed, to the greatest extent possible, without any detrimental effect on the quality of the fibers and without separating, in conjunction with the contaminants, a larger proportion of the fibers.
Fibers from various origins differ in the following characteristics:
Fiber length: The fiber length should not be influenced during the cleaning.
Fiber strength: The fiber strength should not be influenced during the cleaning. The greater the fiber strength, the greater can be the aggressiveness of the cleaning without damage resulting to the fibers.
Fiber parallelism: The more the individual fibers lie parallel to each other, the more uniform are the spaces between the fibers and the less difficult is the separation of the fibers from each other.
Degree of contamination: Particles of contamination lie between the fibers. The degree of contamination is determined by the number and type of the contamination particles.
Type of contamination particles: The contamination particles can be compared with the size of the space in the flocks, small or large; the contamination particles can be compared with the weight of the fibers, heavy or light, and the light contamination particles can be trapped in the spaces of the flocks, either adhering to or loosely contained within the flocks or fibers.
Heretofore, the fine cleaning of textile fibers has been undertaken with fine cleaning machines in which the flocks from the coarse cleaning were somewhat pre-cleaned in a screen or sieve during the operation and compressed into a bat. The bat is then carried further by a feed roller, trapped by a synchronized system by the teeth of the central opening roller and carried with the opening roller for a part of one revolution. During this revolution, the bat is carried past guiding elements and separation blades, alternately. After this cleaning, the bat is withdrawn by suction from the opening roller.
Even though, on such machines, input quantity, air speeds and the rotational speed of the opening roller are altered, and the arrangement of the guide elements and separating blades can be set mechanically, nevertheless, they are not sufficiently versatile, i.e., not sufficiently flexible or adjustable to provide a real guarantee of optimum cleaning in every case. In addition, it is very troublesome and costly to change the fine setting of the machine to adapt the cleaning process for accommodation of fibers having a different origin. Particularly, the fine setting of the cleaning process is not possible during the dynamic operation of the cleaning machine.